RU2056949C1 - Electric precipitator - Google Patents

Abstract

FIELD: gas cleaning. SUBSTANCE: electric precipitator has body 1 with inlet 2 and outlet 3 for gas to be cleaned, corona-forming electrodes 4 and precipitating electrodes 5 formed 5 formed by a row of shaped plates. Each plate-like members made in form of successively connected plates. Each plate is square to the foregoing one. End plates are made of similar lengths, and plate-like members are installed in a row with a gap between them to form through channels for passage of gas. Corona-forming electrodes 4 and precipitating electrodes 5 are installed between inlet 2 and outlet 3 in parallel to gas flow. In row of precipitating electrodes end face plates of plate-like members are parallel to longitudinal plane of symmetry of precipitating electrode at similar distance from it. Ratio between width d of gaps in planes of location of end face plates of adjacent plate-like members and length 1 of end face plate amounts to 0.25-0.50, and ratio between width c of channel between initial and final end face plates in direction of gas flow which are neighboring in row of plate-like members and width d of gap is 0.75-1.5. EFFECT: higher efficiency. 2 dwg

Description

 The invention relates to the purification of gases in electrostatic precipitators and can be used in energy, metallurgy and other industries.

 Closest to the invention is an electrostatic precipitator containing a housing with inlet and outlet nozzles for the gas to be cleaned, corona and precipitation electrodes (OE), while the precipitation electrodes are formed by rows of profiled plate elements made in the form of series-connected plates, each of which is perpendicular to the previous one, with this end plates are made of the same length, plate elements in a row are installed with a gap between them with the formation of through channels for the passage of gas.

 The direction of movement of the gas to be cleaned is perpendicular to the planes of the end plates of the precipitation elements, i.e., the prototype is an electrostatic precipitator with a transverse gas flow. The latter leads to insufficient dust collection efficiency and increased energy consumption for cleaning despite the optimization of the shape of the plate-type precipitation elements in a certain way according to the criterion of increasing the specific deposition efficiency due to, firstly, a reduction in the area of the OE, and secondly, a decrease in the residence time of the dust and gas stream in the near-electrode region of the precipitation electrode ( during transverse motion of the dust and gas flow) and, thirdly, due to an increase in the hydraulic resistance of the apparatus, characteristic for I ESPs with a cross-stroke gas. All of the above reduces the probability of deposition of dust particles on the electrodes.

 The objective of the invention is to increase the degree of purification of gases in the electrostatic precipitator while maintaining the profiled surface of the precipitation electrodes, ensuring their rigidity and compactness.

 The problem is solved due to the optimal placement of the rows of corona and gas-permeable precipitation electrodes relative to the direction of the gas flow and the profiled elements of the precipitation electrode.

 As a result, the longitudinal movement of the dust and gas stream along the surface of the precipitation electrodes is ensured with the simultaneous entry of contaminated gas into the gaps between the profiled deposition elements, which increases the residence time of particles in the near-electrode region due to both an increase in the length of the particle path along a series of precipitation electrodes and due to the simultaneous reducing their speed. Due to these reasons, the probability of dust particle deposition increases and, accordingly, dust collection efficiency increases.

To ensure efficient intake of contaminated gas into the gap between the profiled plate-like deposition elements, the following parameters were experimentally selected:
d (0.25 0.50) l (1)
c (0.75 1.50) d, (2) where d is the width of the gap between the deposition elements in the placement planes of the end plates of adjacent plate elements;
l the length of the end plate of the plate sedimentary elements;
c the width of the channels between the initial and final along the gas end plates of adjacent plate elements in a row.

 The fulfillment of relation (1) ensures the effective penetration and deposition of trapped particles inside the channels between the surfaces of two adjacent plate elements due to the vortex movement (or overflow) of gas and particles in it, since the channel length is limited by parallel surfaces of the end plates of adjacent plate elements, in this case (within 1.0-3.0) is commensurate with the width of the gap, at the boundary of which a vortex gas movement is formed with a characteristic vortex size r equal to the width of the gap.

 For exorbitant values of the d / e ratio (d / e <0.25 or d / e> 0.5), in the first case (d / e <0.25), a channel is formed whose length significantly exceeds the characteristic size of the vortex, which causes inefficient use of the deposition surface inside the channel, since the vortex penetrates into the channel only at a distance commensurate with the size of the vortex, which leads to its inefficient use and to an increase in the material consumption of the precipitation electrode, and in the second case (d / e> 0.5) decrease in degree of cleaning due to surface reduction deposition (as a result of increased clearance).

 The proposed value of the ratio of the width (c) of the channels between the initial and final end plates of the adjacent plate elements in the row to the gap width (d) (2) provides almost free passage of the gas to be cleaned inside the channel and particles are deposited in it, because its hydraulic resistance to gas movement, determined by the characteristic size of the channel width (s), is either slightly larger (≈ 1.5 times, at 0.75 d) the hydraulic resistance to gas passage through the gap (d), or (at c 1.50) significantly (≈ 2.0-2.5 times) less hydraulic resistance to the passage of gas through the gap (d).

 With exorbitant values of the ratio c / d (c / d <0.75 or s / d> 1.5), in the first case (c / d <0.75), the resistance to the passage of contaminated gas increases significantly (more than 1.5 times) inside the channel with a width of (s) and, as a result of the part of the gas not entering the channel, the degree of purification of the electrostatic precipitator is reduced, and in the second case (c / d> 1.50), on the one hand, the degree of gas purification is reduced by increasing the distance between the walls of the channel on which the particles contained in the gas are deposited and, on the other hand, the dimensions (width) of the precipitation element increase ctrode, which, for given values of the discharge distance (h) and the total deposition surface in the electrostatic precipitator, leads to an increase in its dimensions and metal consumption.

 Figure 1 shows an electrostatic precipitator, top view; figure 2 option placement of the electrodes.

 The electrostatic precipitator consists of a housing 1 with an inlet 2 and an outlet 3 nozzles for the gas to be cleaned, corona 4 and gas-permeable precipitation electrodes installed between the nozzles 2 and 3 in parallel with the gas stream. Precipitation electrodes are formed by rows of profiled plate elements 5.

Each of the plate elements 5 is made in the form of series-connected plates 6-8, each of which is perpendicular to the previous one, while the end plates 6 and 8 are made of the same length l. The plate elements 5 in a row are installed with a gap between them with the formation of through channels for the passage of gas. In the "sheet" of the precipitation electrodes, the end plates 6 and 8 are placed parallel to the longitudinal plane of symmetry S of the precipitation electrode at the same distance equal to c / 2. The ratio of the width (d) of the gap in the planes of the placement of the end plates 6 and 8 of the adjacent plate elements 5 to the length l of the end plate (6 = 7 = e) is d / e0.25 0.50, and the ratio of the width (s) of the channel between the initial 6 and end 8 along the gas end plates of adjacent plate elements in a row to the width (d) of the aforementioned gap is
s / d 0.75 1.5
The electrostatic precipitator works as follows.

 The gas to be cleaned through the inlet pipe 2 enters the inlet of the electrostatic precipitator and then into the gas channels between the gas-permeable precipitation electrodes. In the gas channels of the electrostatic precipitator, the particles contained in the gas are charged in the electric field of the corona discharge and, under the action of the forces of this field, are deposited on the surface of the plate elements 5 facing the corona electrodes 4. Some of the particles that have not settled on the outer surfaces of the plate elements 5 are subjected to aerodynamic the gas flow forces initiating the vortex gas movement in the channels between adjacent plate elements 5 are captured by the vortex (r) and deposited on the surfaces of the plate elements inside the channel s.

 When organizing the longitudinal-transverse (combined) movement of the gas being cleaned in the active part of the electrostatic precipitator by installing plugs 9 in a checkerboard pattern at the inlet and outlet of the gas channels (Fig. 2), gas flows from the channel to the channel while particles are deposited on both the outer surfaces of the plate elements 5, so on the inside.

 Due to the high stiffness of the profiled plate elements, the dust layer on the surface of the plate elements, formed from settled particles, is rather efficiently removed into the hopper, including with an increased length (height) of the collecting electrodes, for example, by means of hammer tapping.

 Using the proposed electrostatic precipitator will allow for efficient cleaning of large volumes of gas streams.

Claims (1)

 ELECTROFILTER containing a housing with inlet and outlet nozzles for the gas to be cleaned, corona and precipitation electrodes, while the precipitation electrodes are formed by rows of profiled plate elements made in the form of series-connected plates, each of which is perpendicular to the previous one, and the end plates are made of the same length, and plate elements in a row are installed with a gap between them with the formation of through channels for the passage of gas, characterized in that the corona and precipitation electrodes are installed between the nozzles parallel to the gas flow, while in the rows of profiled plate elements of the precipitation electrodes, the end plates of the plate elements are placed parallel to the longitudinal plane of symmetry of the precipitation electrode and at the same distance from it, and the ratio of the width d of the gaps in the planes of the end plates of adjacent plate elements to the length l of the end plate is 0.25 - 0.50, and the ratio of the width c of the channel between the initial and final end plates along the gas Steen adjacent plate elements in the row to the gap width d is 0,75 - 1,5.

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